Barcode Number Systems: GTIN, UPC, EAN & ISBN
How product numbering systems assign unique identifiers — GTIN-8, GTIN-12, GTIN-13, GTIN-14, and the relationship between UPC, EAN, and ISBN.
Barcode Number Systems: GTIN, UPC, EAN & ISBN
The numbers encoded in product barcodes follow carefully designed numbering systems that ensure every product, book, and logistics unit has a globally unique identifier. Understanding these systems is essential for anyone working with barcodes.
GTIN: The Unified Framework
The Global Trade Item Number (GS1 Standards & Identifiers">GTIN) is the umbrella framework managed by GS1 that encompasses all product identification numbers. Every UPC, EAN, and ISBN number is a GTIN:
| Format | Digits | Encoded In | Common Name |
|---|---|---|---|
| space." data-category="1D Linear Symbologies">EAN-8 barcodes." data-category="GS1 Standards & Identifiers">GTIN-8 | 8 | EAN-8 | Short EAN |
| UPC-A barcodes in North America." data-category="GS1 Standards & Identifiers">GTIN-12 | 12 | UPC-A | UPC number |
| EAN-13, the global standard." data-category="GS1 Standards & Identifiers">GTIN-13 | 13 | EAN-13 | EAN number |
| ITF-14 barcodes on cases and pallets." data-category="GS1 Standards & Identifiers">GTIN-14 | 14 | ITF-14 | Case code |
All four can be represented as a 14-digit GTIN by zero-padding on the left. A UPC number 614141999996 becomes GTIN-14 00614141999996.
UPC Numbering
The Universal Product Code (UPC) is the 12-digit numbering system used primarily in North America. A UPC-A number has three parts:
- Company prefix (6-10 digits assigned by GS1 US)
- Item reference (1-5 digits assigned by the company)
- Check digit (1 digit, calculated)
Since 2005, all UPC scanners must also read 13-digit EAN numbers, effectively making UPC a subset of the EAN system (a UPC is an EAN-13 with a leading zero).
EAN Numbering
The European Article Number (EAN) is the 13-digit system used worldwide. Its structure mirrors UPC:
- GS1 prefix (3 digits identifying the country of the issuing GS1 organization)
- Company prefix (variable length)
- Item reference (variable length)
- Check digit (1 digit)
Note that the GS1 prefix indicates where the company registered, not where the product was manufactured. A product with prefix 880 (South Korea) could be made anywhere.
ISBN Numbering
The International Standard Book Number is a 13-digit identifier for books, always beginning with prefix 978 or 979 (Bookland). ISBN-13 numbers are encoded in standard EAN-13 barcodes. An optional 5-digit supplemental barcode beside the main symbol encodes the suggested retail price.
The older ISBN-10 format was retired in 2007. Converting ISBN-10 to ISBN-13 involves prepending "978" and recalculating the check digit.
ISSN Numbering
The International Standard Serial Number identifies periodicals. An ISSN is 8 digits, encoded in an EAN-13 barcode with prefix 977. A 2-digit supplemental barcode can indicate the issue number.
SSCC: Logistics Units
The Serial Shipping Container Code is an 18-digit number that identifies logistics units (pallets, cases). It is encoded in GS1-128 barcodes with GS1-128 barcodes." data-category="GS1 Standards & Identifiers">Application Identifier (00). SSCCs enable tracking of shipments from warehouse to delivery.